British Journal of Anaesthesia, 1995, Vol. 74, No. 6 674-680
© 1995 The Board of Management and Trustees of the British Journal of Anaesthesia
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The P300 event-related potential during propofol sedation: a possible marker for amnesia?
Memorial Sloan-Kettering Cancer Center New York, NY, USA
Present address: Instituto di Anestesia e Rcanimazione, Universitá di Roma "La Sapienza" Rome, Italy
Memorial Sloan-Kettering Cancer Center and Cornell University Medical College New York, NY, USA
Address for correspondence: Memorial Sloan-Kertering Cancer Center, Department of Anesthesiology and Critical Care Medicine, 1275 York Avenue, New York, NY 10021, USA
We have studied the effects of conscious sedation with propofol on long latency components of the auditory event-related potential (ERP) in 10 normal volunteers (aged 2141 yr) receiving propofol 75 µg kg1 min1 i.v. We examined the effects of propofol on ERP amplitudes and latencies, and their relationship to delayed recognition performance using a verbal memory test, a selective attention task (button pushing) and serum concentrations of propofol. During infusion of propofol, subjects were mildly sedated, oriented and readily responsive to verbal commands. ERP were recorded from monopolar Fz, Cz and Pz electrodes. We used a standard paradigm requiring selective attention to randomly occurring stimuli associated with a task (button push). The peak-to-peak amplitudes and latencies of the N2 and P3 waves were obtained before and during infusion, and 15, 100 and 170min after infusion. Propofol produced a 70% decrease in the amplitude of P3 (P < 0.0001) from baseline and a 50% increase in reaction time. The differential response to target compared with non-target stimuli was maintained during infusion for both N2 and P3. Memory performance correlated more strongly with changes in P3 amplitude (r = 0.59) than with serum propofol concentrations (r = 0.07), although this correlation with memory did not reach statistical significance (P = 0.08). We conclude that P3 amplitude was profoundly affected by propofol given in sedative concentrations.
Presented in part at the annual meeting of the American Society of Anesthesiologists, New Orleans, LA, October 17-21, 1992